Hello John, it could well have been the sodium, however Megan is right in advising you to contact our myeloma nurse or your haematology nurse, my Mum had seizures due to her pain medication she was on oxycontin at the time which when reduced and changed to oxynorm stopped. Mums sodium level also dropped after starting Velcade, her fluid intake was reduced at home at the request of her Dr, she ended up on the oncology ward and they improved her condition but i am unsure what they did there for her.Sometimes infections cause problems, but hopefully you will know more on friday, hopefully she will have no more seizures, best wishes to you both San xx